[Boost-bugs] [Boost C++ Libraries] #10818: A C4267 "possible loss of data" warning when compiling on VS2013 x64 with /W4

Subject: [Boost-bugs] [Boost C++ Libraries] #10818: A C4267 "possible loss of data" warning when compiling on VS2013 x64 with /W4
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-11-26 06:14:30

#10818: A C4267 "possible loss of data" warning when compiling on VS2013 x64 with
/W4
------------------------------+----------------------------
 Reporter:  kaa123@…          |      Owner:  jsiek
     Type:  Bugs              |     Status:  new
Milestone:  To Be Determined  |  Component:  dynamic_bitset
  Version:  Boost 1.56.0      |   Severity:  Cosmetic
 Keywords:                    |
------------------------------+----------------------------
 Example:
   boost::dynamic_bitset<> flags;
 ...
   bool b = flags[56];
 Warning when calling the reference class constructor from the [] operator.

 Compiler -- VS2013, Platform -- x64, Debug mode, Warning level -- /W4.

 Fix:  I found if you changed the pos parameter of the reference class
 constructor to size_type, the warning went away.

 From:
   reference(block_type & b, block_type pos)
 To:
   reference(block_type & b, size_type pos)
 Location Line 88 of dynamic_bitset.hpp


 Actual error message:

 4>C:\Boost\1_56_0-VS_2013-x64\include\boost-
 1_56\boost/dynamic_bitset/dynamic_bitset.hpp(296): warning C4267:
 'argument' : conversion from 'size_t' to 'unsigned long', possible loss of
 data
 4>          C:\Boost\1_56_0-VS_2013-x64\include\boost-
 1_56\boost/dynamic_bitset/dynamic_bitset.hpp(295) : while compiling class
 template member function 'boost::dynamic_bitset<unsigned
 long,std::allocator<Block>>::reference
 boost::dynamic_bitset<Block,std::allocator<Block>>::operator
 [](boost::dynamic_bitset<Block,std::allocator<Block>>::size_type)'


 reference(block_type & b, size_type pos)

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10818>
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